Refrigerator cabinet



Dec. 27, 1938; J, L KN T 2,141,918

REFRIGERATOR CABINET Filed May 17, 1938 Fi l. 7''

i 5 '1lllllllfllllllllllllllwglLa 1 Inventor: James L. Knight,

l-ii s ttohn e Patented Dec. 27, 1938 UNITED STATES REFRIGERATOR CABINET James L. Knight, Erie, Pa, assignor to General Electric Company, a corporation of New York Application May 17, 1938, Serial No. 208,375

3 Claims.

My invention relates to refrigerator cabinets and particularly to devices for preventing condensation of moisture on the outside of such cabinets.

Refrigerator cabinets, particularly those provided with a plurality of doors frequently have portions of their outside surface which may be cooled to temperatures below the dew point of the surrounding air and thereby cause condensation of moisture on the cabinet walls. For example, the mullion provided between the doors of a two door cabinet has an outside surface which is insulated from the remainder of the outside surface of the cabinet by the door gaskets. Furthermore, since the door does not normally contact the jamb but rests on the door gasket, there is a space between the door and the surrounding gasket through which cold air may circulate from the cabinet interior thereby increasing the cooling effect along the mullion. Domestic refrigerators are frequently provided with cabinets in the lower portion of which is arranged a machine compartment containing the condensing unit for supplying refrigerant to the evaporator. Accordingly, it is an object of my invention to provide a refrigerator including a cabinet having an evaporator therein and a condensing unit for supplying refrigerant to the evaporator and including an improved arrangement for utilizing the heat of the condensing unit to prevent condensation of moisture on the walls of the cabinet.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize myinvention will be pointed out with particularity in the claims annexed to and forming a. part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 shows a two door refrigerator cabinet embodying my invention; and Fig. 2 is an enlarged sectional elevation of the mullion heating device shown in Fig. 1.

Referring to the drawing. in Fig.1 I have shown I a household refrigerator having a cabinet III with doors II and I2 and a central mullion l3 arranged between the door openings. Within the upper portion of the cabinet is a thermally insulated cooling compartment I4 and in the lower section of the cabinet there is a machine compartment iii. In the compartment i5 are ar-- ranged a condensing unit comprising a sealed casing l6 containing a motor driven compressor and a condenser ll over which air is circulated by operation of a fan l8. An evaporator I9 is arranged within the cabinet compartment ll for cooling the air therein, and refrigerant is supplied to the evaporator I9 from the condensing unit. Referring now toFig. 2, the mullion l3 5 comprises an inner metal wall 20 and an outer metal wall 2| connected by insulating strips 22, the interior of the mullion being filled with heat insulating material 23. It will be noted that the inner surface 20' is of greater area than the 10 outer surface 2|, and, consequently, this increases the tendency to cool the outer surface. It will also be noted that there is an air space between the strips 22 and the doors II and I2 and that cold air can circulate in this space and increase 16 the removal of heat from the outer surface 2| of the mullion. Conduction of heat through the strips 22 alsoremoves heat from the outer surface of the mullion. The outer surface of the mullion is separated along both sides by the door :0 gaskets indicated at 24 and 25 on the doors H and I2 respectively, and very little heat can flow to the outer surface of the mullion from the cabinet and door surfaces. The outside surface of the mullion will, therefore, be cooled more than 25 the outside surface of the remainder of the cabinet and, in many cases, this cooling effect is suflicient to lower the temperature of the outside surface of the'mullion below the dew point of the surrounding air and there is, therefore, a condensation of moisture onthe outside surface. This condensation is obviously objectionable.

In order to heat the mullion and prevent the cooling thereof to temperatures below the dew point of the surrounding air, I provide a tube or elongated container 26 which is hermetically sealed and partially filled with refrigerant or other volatile liquid. The upper portion'of the tube 26 is vertical and is arranged within the mullion longitudinally thereof; the lower por- 40 tion of the tube projects into the compartment l5 containing the condensing unit and the lowermost end thereof is secured in heat conducting relation to the wall of the casing l6 by a bracket 21. The'liquid within the tube 26 collects in the bottom and is heated by conduction of heat from the casing lB,and some of the liquid is thereby vaporized and flows upwardly to the vertical portion of the tube where it delivers its heat to the mullion and is thereby cooled and condensed, the condensate flowing back tothe lower end of the tube. This vaporization and condensation of the volatile liquid continually transfers heat from the casing IE to the mullion and thereby prevents a reduction of the temperature of the outside surface of the mullion below the dew point of the surrounding air. The amount of heating which may be eflected by the tube 26 is determined by the amount of liquid charge originally sealed into the tube, and it is, therefore, possible to design the tube to supply no more heat than is necessary to insure the maintaining of the outer surface of the mullion above the dew point of the surrounding air; excess heating of the mullion is thus prevented.

While I have described my invention in connection with a household refrigerator of the type having a mullion between two doors, it will be apparent that it is applicable to other constructions in which it is desired to transfer heat from the condensing unit to a portion of the cabinet surface. I do not, therefore, desire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications thereof which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is;

1. A refrigerating machine including a cabinet, a refrigerant evaporator for cooling said cabinet, means including a condensing unit for supplying refrigerant to said evaporator, one portion of the outer surface of said cabinet being so arranged that it may be cooled below the dew point of the surrounding air by operation of said evaporator, and means including a hermetically sealed container partially filled with a volatile liquid for transferring heat from said condensing unit to said portion of said outer surface to maintain the temperature of said portion of said surface above the dew point of the surrounding air.

2. A refrigerating machine including a cabinet having thermally insulated walls, a refrigerant evaporator for cooling said cabinet, means including a condensing unit for supplying refrigerant to said evaporator, one portion of said cabinet walls having a relatively small outer surface area and being thermally insulated from the remainder of the outer walls of said cabinet over substantially its entire boundary, a hermetically sealed container partially filled with a volatile liquid, said container having a part thereof arranged within said one portion of said walls and another part thereof arranged below said first part and in heat conducting relation with said condensing unit to convey heat from said unit to said portion of said walls.

3. A refrigerating machine including a thermally insulated cabinet having two door openings and a mullion therebetween, doors for closing said openings, a refrigerant evaporator for cooling the interior of said cabinet, means including a condensing unit arranged below said cabinet for supplying refrigerant to said evaporator, and means for preventing condensation of moisture on the outer wall of said mullion, said last-mentioned means including an elongated container partially filled with a volatile liquid and hermetically sealed, one portion of said container being arranged within said mullion and another portion being secured in heat conducting relation with said condensing unit below said mullion. 

